Wind turbine

A wind turbine is a machine converting the wind energy in mechanical energy then in electrical energy. The energy conversion is made by a turbine driving an electrical generator (DC or more often multiphase AC ) . Technically, the main figures of merit for classifying a wind turbine are :

the highest rate of wind energy that is converted to mechanical energy in the limit of physical laws

the highest efficiency of the conversion from mechanical energy to electrical energy

the lowest windspeed for initiating energy production

the most silent operation at a given windspeed

There are 2 mains kinds of wind turbines: Horizontal Axis Wind Turbines or HAWT, Vertical Axis Wind Turbines or VAWT. The HAWT generally rotate at higher speed than VAWT for a given windspeed. For a given power, the HAWT have consequently a lower torque and smaller generator or alternator than VAWT, but they are generally less silent than VAWT. That is the reason why the VAWT are considered more particularly for use in urban environment.